4Paul Graham, A Plan For Spam,2002.08; Better Bayesian Filtering,2003,01 ;Filters That Fight Back,2003.08 ;Stopping Spare ,2003.08.
5Gary Robinson, Gary Robinson's Spam Rants, 2003.06.27 - 2003.10.02.
6William S. Yerazunis. The Spam-Filtering Accuracy Plateau at 99.9% Accuracy and How to Get Past It ,Presented at the 2004 M1T Spam Conferenct,January 18,2004.